This application is related to an application entitled xe2x80x9cImproved Method for Preparing Small Particle Size Glucanxe2x80x9d and an application entitled xe2x80x9cImproved Method for Preparing Small Particle Size Glucan in a Finely Dispersed Powderxe2x80x9d filed on the same day as the present application.
The present invention relates generally to an improved method for the preparation of small particle size glucan in a dry material. More particularly, the present invention relates to the preparation of small particle size glucans in a dry material that modulate immunological activity in humans and animals.
Glucans are polymers of glucose. Glucans are commonly found in the cell walls of bacteria, yeast, and various plant species. A common glucan is beta (1,3)-linked glucopyranose (commonly referred to as beta glucan). Other common examples include mixtures of beta-(1,3)-linked glucopyranose with beta-(1,6)-linked glucopyranose. These glucans have been shown to have immunopharmacological activity in humans and animals. More particularly, beta (1,3) glucan has been shown to effect some immune responses.
The prior art does contain methods of preparation of a glucan containing composition, but not a stable small particle size glucan containing composition.
For example, U.S. Pat. No. 5,576,015 to Donzis discloses the use of a beta glucan as both a nutritional and topological agent. The ""015 patent discloses that beta (1,3) glucan may be combined with a suitable pharmaceutical carrier for topical application to the skin. Further, the ""015 patent discloses that beta (1,3) glucan may be administered orally. As well, the ""015 patent discloses that a small particle size glucan is preferred to a glucan product which comprises larger sized glucan particles. However, the ""015 patent does not explain why the small particle size is desirable nor whether a small particle size glucan is necessary or even how to achieve and maintain the small particle size glucan.
A preferred size of the glucan particle disclosed in the ""015 patent is one micron in diameter. Accordingly, the ""015 patent discloses that a beta glucan may be more immunologically effective the smaller the particle size of the beta glucan. However, the method of grinding beta glucan disclosed by Donzis does not effectively produce a consistent small particle size beta glucan. Additionally, no matter to what size the grinding reduces the glucan, the glucan containing composition prepared by the ""015 patent re-aggregates into a large particle size glucan upon hydration. Accordingly, the ""015 patent does not disclose a reliable method of producing a fine grind beta glucan in which the particle size of a glucan is predominantly one micron or less.
Various methods exist in the prior art for the production of glucan containing compositions. However, only soluble glucan has been created in a substantially purified form to date. Methods of producing insoluble glucan produce glucan containing compositions in which the glucan is not in a substantially purified form. A general method for the production of glucan containing compositions from yeast involves extraction with alkali followed by extraction with acid. This method is considered to be extremely time consuming and labor intensive and was described in detail in 1991 in an article published in Carbohydrate Research. (Nicholas R. Di Luzio et al., xe2x80x9cA method of solubilization of a (1-3)-B-D-glucan isolated from Saccharomyces cerevisiae,xe2x80x9d 219 Carbohydrate Research, 203-213 (1991).
Another more modem method is disclosed in U.S. Pat. No. 5,223,491 to Donzis. The improved method of Donzis discloses a primary difference from that of previous preparation methods in that yeast material is first autoclaved in an alkali solution, followed by an acid extraction and ethanol wash. The patent states the method produces a particularly potent insoluble glucan product which is substantially free of protein and non-glucose sugars, and which significantly stimulates the activities of macrophages. However, studies conducted on the product of the ""491 patent indicate that the product was substantially more protein than glucan. Further, the method of the ""491 patent allows the glucan to re-aggregate upon re-hydration to an aggregate size of greater than one micron in diameter. As the glucan re-aggregates to a size of greater than one micron in diameter, some of the beneficial effect of the glucan is not achieved because the macrophage receptors are not activated as readily by glucan greater than one micron in diameter because the receptor size on corresponding cells and molecules that accept the glucan is generally about one micron in size.
The re-aggregation and resistance to de-aggregation is accentuated in environments with low pH such as a human digestive tract, such as at a pH of less than 1.0. As the glucan re-aggregates into particles of greater than one micron in diameter, it appears to pass through an animal or human digestive system without substantially complete absorption.
Accordingly, the art field has searched for a reliable method to produce substantially purified glucan aggregates that remain substantially in a particle size of one micron in diameter or less throughout preparation and packaging without re-aggregation.
The present invention generally relates to the preparation of a dry glucan product that substantially de-aggregates upon hydration into particles of 1 micron or less.
This summary is not intended to be a limitation with respect to the features of the invention as claimed, and this and other objects can be more readily observed and understood in the detailed description of the preferred embodiment and the claims that follow.